/*
 * ResourceAction.java 8 juil. 2006
 *
 * Sweet Home 3D, Copyright (c) 2006 Emmanuel PUYBARET / eTeks <info@eteks.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
package com.eteks.sweethome3d.swing;

import java.awt.event.ActionEvent;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.lang.ref.WeakReference;

import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.ImageIcon;
import javax.swing.KeyStroke;
import javax.swing.event.SwingPropertyChangeSupport;

import com.eteks.sweethome3d.model.UserPreferences;
import com.eteks.sweethome3d.tools.OperatingSystem;

/**
 * An action with properties read from a resource bundle file.
 * @author Emmanuel Puybaret
 */
public class ResourceAction extends AbstractAction
{
	public static final String POPUP = "Popup";
	public static final String TOGGLE_BUTTON_MODEL = "ToggleButtonModel";
	
	/**
	 * Creates a disabled action with properties retrieved from a resource bundle 
	 * in which key starts with <code>actionPrefix</code>.
	 * @param preferences   user preferences used to retrieve localized properties of the action 
	 * @param resourceClass the class used as a context to retrieve localized properties of the action
	 * @param actionPrefix  prefix used in resource bundle to search action properties
	 */
	public ResourceAction(UserPreferences preferences, Class<?> resourceClass, String actionPrefix)
	{
		this(preferences, resourceClass, actionPrefix, false);
	}
	
	/**
	 * Creates an action with properties retrieved from a resource bundle 
	 * in which key starts with <code>actionPrefix</code>.
	 * @param preferences   user preferences used to retrieve localized description of the action
	 * @param resourceClass the class used as a context to retrieve localized properties of the action
	 * @param actionPrefix  prefix used in resource bundle to search action properties
	 * @param enabled <code>true</code> if the action should be enabled at creation.
	 */
	public ResourceAction(UserPreferences preferences, Class<?> resourceClass, String actionPrefix, boolean enabled)
	{
		readActionProperties(preferences, resourceClass, actionPrefix);
		setEnabled(enabled);
		
		preferences.addPropertyChangeListener(UserPreferences.Property.LANGUAGE,
				new LanguageChangeListener(this, resourceClass, actionPrefix));
	}
	
	/**
	 * Preferences property listener bound to this action with a weak reference to avoid
	 * strong link between preferences and this action.  
	 */
	private static class LanguageChangeListener implements PropertyChangeListener
	{
		private final WeakReference<ResourceAction> resourceAction;
		private final Class<?> resourceClass;
		private final String actionPrefix;
		
		public LanguageChangeListener(ResourceAction resourceAction, Class<?> resourceClass, String actionPrefix)
		{
			this.resourceAction = new WeakReference<ResourceAction>(resourceAction);
			this.resourceClass = resourceClass;
			this.actionPrefix = actionPrefix;
		}
		
		public void propertyChange(PropertyChangeEvent ev)
		{
			// If action was garbage collected, remove this listener from preferences
			ResourceAction resourceAction = this.resourceAction.get();
			if (resourceAction == null)
			{
				((UserPreferences) ev.getSource()).removePropertyChangeListener(UserPreferences.Property.LANGUAGE,
						this);
			}
			else
			{
				resourceAction.readActionProperties((UserPreferences) ev.getSource(), this.resourceClass,
						this.actionPrefix);
			}
		}
	}
	
	/**
	 * Reads from the properties of this action.
	 */
	private void readActionProperties(UserPreferences preferences, Class<?> resourceClass, String actionPrefix)
	{
		String propertyPrefix = actionPrefix + ".";
		putValue(NAME, getOptionalString(preferences, resourceClass, propertyPrefix + NAME, true));
		putValue(DEFAULT, getValue(NAME));
		putValue(POPUP, getOptionalString(preferences, resourceClass, propertyPrefix + POPUP, true));
		
		putValue(SHORT_DESCRIPTION,
				getOptionalString(preferences, resourceClass, propertyPrefix + SHORT_DESCRIPTION, false));
		putValue(LONG_DESCRIPTION,
				getOptionalString(preferences, resourceClass, propertyPrefix + LONG_DESCRIPTION, false));
		
		String smallIcon = getOptionalString(preferences, resourceClass, propertyPrefix + SMALL_ICON, false);
		if (smallIcon != null)
		{
			putValue(SMALL_ICON, SwingTools.getScaledImageIcon(resourceClass.getResource(smallIcon)));
		}
		
		String propertyKey = propertyPrefix + ACCELERATOR_KEY;
		// Search first if there's a key for this OS
		String acceleratorKey = getOptionalString(preferences, resourceClass,
				propertyKey + "." + System.getProperty("os.name"), false);
		if (acceleratorKey == null)
		{
			// Then search default value
			acceleratorKey = getOptionalString(preferences, resourceClass, propertyKey, false);
		}
		if (acceleratorKey != null)
		{
			putValue(ACCELERATOR_KEY, KeyStroke.getKeyStroke(acceleratorKey));
		}
		
		String mnemonicKey = getOptionalString(preferences, resourceClass, propertyPrefix + MNEMONIC_KEY, false);
		if (mnemonicKey != null)
		{
			putValue(MNEMONIC_KEY, Integer.valueOf(KeyStroke.getKeyStroke(mnemonicKey).getKeyCode()));
		}
	}
	
	/**
	 * Returns the value of <code>propertyKey</code> in <code>preferences</code>, 
	 * or <code>null</code> if the property doesn't exist.
	 */
	private String getOptionalString(UserPreferences preferences, Class<?> resourceClass, String propertyKey,
			boolean label)
	{
		try
		{
			String localizedText = label ? SwingTools.getLocalizedLabelText(preferences, resourceClass, propertyKey)
					: preferences.getLocalizedString(resourceClass, propertyKey);
			if (localizedText != null && localizedText.length() > 0)
			{
				return localizedText;
			}
			else
			{
				return null;
			}
		}
		catch (IllegalArgumentException ex)
		{
			return null;
		}
	}
	
	/**
	 * Unsupported operation. Subclasses should override this method if they want
	 * to associate a real action to this class.
	 */
	public void actionPerformed(ActionEvent ev)
	{
		throw new UnsupportedOperationException();
	}
	
	/**
	 * An action decorator.  
	 */
	private static class AbstractDecoratedAction implements Action
	{
		private Action action;
		private SwingPropertyChangeSupport propertyChangeSupport;
		
		public AbstractDecoratedAction(Action action)
		{
			this.action = action;
			this.propertyChangeSupport = new SwingPropertyChangeSupport(this);
			action.addPropertyChangeListener(new PropertyChangeListener()
			{
				public void propertyChange(PropertyChangeEvent ev)
				{
					String propertyName = ev.getPropertyName();
					if ("enabled".equals(propertyName))
					{
						propertyChangeSupport.firePropertyChange(ev);
					}
					else
					{
						Object newValue = getValue(propertyName);
						// In case a property value changes, fire the new value decorated in subclasses
						// unless new value is null (most Swing listeners don't check new value is null !)
						if (newValue != null)
						{
							propertyChangeSupport.firePropertyChange(
									new PropertyChangeEvent(ev.getSource(), propertyName, ev.getOldValue(), newValue));
						}
					}
				}
			});
		}
		
		public final void actionPerformed(ActionEvent ev)
		{
			this.action.actionPerformed(ev);
		}
		
		public final void addPropertyChangeListener(PropertyChangeListener listener)
		{
			this.propertyChangeSupport.addPropertyChangeListener(listener);
		}
		
		public Object getValue(String key)
		{
			return this.action.getValue(key);
		}
		
		public final boolean isEnabled()
		{
			return this.action.isEnabled();
		}
		
		public final void putValue(String key, Object value)
		{
			this.action.putValue(key, value);
		}
		
		public final void removePropertyChangeListener(PropertyChangeListener listener)
		{
			this.propertyChangeSupport.removePropertyChangeListener(listener);
		}
		
		public final void setEnabled(boolean enabled)
		{
			this.action.setEnabled(enabled);
		}
		
		protected void firePropertyChange(String propertyName, Object oldValue, Object newValue)
		{
			this.propertyChangeSupport.firePropertyChange(propertyName, oldValue, newValue);
		}
	}
	
	/**
	 * An action decorator for menu items.  
	 */
	public static class MenuItemAction extends AbstractDecoratedAction
	{
		public MenuItemAction(Action action)
		{
			super(action);
		}
		
		public Object getValue(String key)
		{
			// Avoid mnemonics, tooltips and icons in Mac OS X menus
			if (OperatingSystem.isMacOSX()
					&& (key.equals(MNEMONIC_KEY) || key.equals(SMALL_ICON) || key.equals(SHORT_DESCRIPTION)))
			{
				return null;
			}
			return super.getValue(key);
		}
	}
	
	/**
	 * An action decorator for popup menu items.  
	 */
	public static class PopupMenuItemAction extends MenuItemAction
	{
		public PopupMenuItemAction(Action action)
		{
			super(action);
			// Add a listener on POPUP value changes because the value of the 
			// POPUP key replaces the one matching NAME if it exists       
			addPropertyChangeListener(new PropertyChangeListener()
			{
				public void propertyChange(PropertyChangeEvent ev)
				{
					if (POPUP.equals(ev.getPropertyName()) && (ev.getOldValue() != null || ev.getNewValue() != null))
					{
						firePropertyChange(NAME, ev.getOldValue(), ev.getNewValue());
					}
				}
			});
		}
		
		public Object getValue(String key)
		{
			// If it exists, return POPUP key value if NAME key is required 
			if (key.equals(NAME))
			{
				Object value = super.getValue(POPUP);
				if (value != null)
				{
					return value;
				}
			}
			else if (key.equals(SMALL_ICON))
			{
				// Avoid icons in popus
				return null;
			}
			else if (OperatingSystem.isMacOSX() && key.equals(ACCELERATOR_KEY))
			{
				// Avoid accelerators in Mac OS X popups
				return null;
			}
			return super.getValue(key);
		}
	}
	
	/**
	 * An action decorator for tool bar buttons.  
	 */
	public static class ToolBarAction extends AbstractDecoratedAction
	{
		public ToolBarAction(Action action)
		{
			super(action);
		}
		
		public Object getValue(String key)
		{
			// Ignore NAME in tool bar 
			if (key.equals(NAME))
			{
				return null;
			}
			return super.getValue(key);
		}
	}
	
	/**
	 * An action decorator for  buttons.  
	 */
	public static class ButtonAction extends AbstractDecoratedAction
	{
		public ButtonAction(Action action)
		{
			super(action);
		}
		
		public Object getValue(String key)
		{
			// Avoid mnemonics in Mac OS X menus
			if (OperatingSystem.isMacOSX() && key.equals(MNEMONIC_KEY))
			{
				return null;
			}
			return super.getValue(key);
		}
	}
}
